1. Field of the Invention
The present invention relates to a satellite broadcasting system and a satellite broadcasting reception apparatus for digital satellite broadcasting provided to users of cars, and more particularly to a satellite broadcasting system and a satellite broadcasting reception apparatus by which selective reception of digital satellite broadcasting is allowed.
2. Description of the Related Art
Digital satellite broadcasting is being popularized in various countries including Japan and the United States.
One of significant differences of digital satellite broadcasting from ground wave broadcasting is that simultaneous broadcasting over a wide area is possible. The overall land of Japan can be covered only by a single satellite, and also the overall land of the United States is covered by a small number of satellites. On the other hand, if it is tried to cover the overall land of Japan using ground wave broadcasting, then since the ground wave broadcasting must be repeated by local related broadcasting stations, a very high maintenance cost is required. The difference in cost is significant particularly where an advertisement is broadcast. Where an image advertisement of a large corporation wherein the same contents are advertised over the overall land is involved, the cost is lower where satellite broadcasting is used.
Meanwhile, an advertisement is sometimes different in significance depending upon a district. For example, when it is desired to broadcast an advertisement (CM) of goods for a snowy district in a snowy district, there is no meaning if the advertisement is broadcast in Okinawa in which it does not snow. Further, it is impossible for a local minor maker to pay the fare for a CM to be broadcast over the overall country, and where a distribution channel is not developed except the district of the maker, it is considered sufficient if the CM is broadcast only in the district.
Further, in such a nation in which the authorities of local governments are strong such as the United States, contents which can be advertised may be different among different states. For example, advertisement of liquors may be prohibited in some state, or advertisement of guns may be inhibited in another state. In such a case, since a broadcasting station cannot broadcast an advertisement of liquors in a state in which advertisement of liquors is prohibited, it is necessary to segment the nation into several districts and apply different advertisement contents to the districts. Ground wave broadcasting is suitable for such advertisement.
In this manner, while satellite broadcasting is convenient where the same CM or the same broadcasting contents are to be broadcast all at once over the overall nation, it
cannot be broadcast in different contents to segmented districts of the nation. Naturally, digital satellite broadcasting makes it possible to allocate different channels to different districts because a greater number of channels than that which can be assured by analog broadcasting can be assured by digital compression. However, this is wasteful in that a plurality of channels are used wastefully. For example, in the United State, if a broadcasting area is segmented in a unit of a state, then one channel is allocated to each state, and 50 channels are required for the 50 states. Since broadcasting of the 50 channels is broadcast over the overall nation, some waste occurs.